A Study on Marine Transport Database
Ayuko NAKAJMA, Ruri SHOJI, Zen Heitoh, Masaki OSHIMA · The Journal of Japan Institute of Navigation · 2007
This paper argues about the marine traffic database system based on the automatic wake extraction from radar signals. The system aids the maritime security for congested sea lanes and area, offering the automatic surveillance functions. Moreover, the database should be useful for the planning and the designing for sea routes or harbors by fast range retrieval of the stored wakes. The radar station located in Yokosuka, the shore of the Tokyo Bay, is remotely operable via the Internet and the stored signals can be downloaded. The wakes are extracted from the signals using some image processing techniques such as dynamic background subtraction. Though the wake of a ship tends to be divided into many pieces due to the sea clutter, it is easy to find the adjacent or related pieces of a wake through GUI and the range retrieval function provided by the system. The system employs R^*-Tree as the data structure for indexing and range retrieval of the pieces of wakes. In the experiments, the system can retrieve the wakes twice as fast as a linear search.